(1) Field of the Invention
The invention relates to a method to manufacture a product, and, more particularly, to a method to formulate chamber selections for multiple chamber tools in the manufacture of an integrated circuit device.
(2) Description of the Prior Art
Integrated circuit manufacturing presents many unique challenges. The typical process cycle takes many days, or weeks, and requires a large number of complex steps. Much of the processing is performed in batches, or lots, or wafers. These lots must be tracked throughout the process cycle to ensure that the proper processing sequence has been performed.
Referring now to FIG. 1, the architecture for an exemplary manufacturing line is shown. The manufacturing process can be divided into two general classes, the manufacturing control system 10 and the manufacturing equipment 20. The manufacturing equipment 20 comprises a collection of processing tools 40, 44, and 48, that are used during the processing sequence for manufacturing the integrated circuit wafers. At particular steps in the process flows, one lot or several lots of wafers are loaded into process tools. A process step, such as etching, thermal processing, deposition, or ion implantation, is then performed on the wafers in the tool.
Each process tool 40, 44, and 48, comprises a control unit and a process chamber. TOOL00348 comprises a single process chamber. TOOL00140 and TOOL00244 are multiple chamber tools. For example, TOOL00140 comprises two processing chambers, labeled A and B. TOOL00244 comprises four processing chambers, labeled A, B, C, and D. The multiple chamber tools 40 and 44 may be configured so that the chambers run independently. That is, one chamber may run a first processing variation, or recipe, while another chamber runs a second recipe. The presence of independent, multiple chambers makes the multiple chamber tools 40 and 44 very useful for the manufacturer. Typically, such tools require less floor space and utilities than an equivalent number of chambers in single chamber tools 48.
The manufacturing process is managed by the manufacturing control system 10. With the advent of high speed computers and highly developed software, much of the decision making on the manufacturing floor is now under the control of the computer system. The exemplary system 10 comprises a manufacturing execution system (MES) running on a server 24. For example, PROMIS™ software is frequently used for the MES role. The PROMIS™ server 24 comprises a database 33 that tracks every product lot in the manufacturing facility. The processing history and current status of each lot is stored along with the routing flow for the product. The PROMIS™ server 24 also performs a role in selecting recipes to be run on the processing tools 40, 44, and 48.
A CONSTRAINT MANAGER (CSN™) server 28 is used to track equipment resources in the manufacturing facility. The CSN™ server 28 selects the most appropriate processing tool for the next step in the processing flow for a particular lot to maximize line throughput and to minimize cycle time. Further, the CSN™ server 28 can perform chamber selection within a tool. The RUN MANAGER (RM™) server 32 is used to manage the actual process runs in the plant. The RM™ server 32 performs error prevention routines and maintains a process run database 33.
The EQUIPMENT SERVER (EQS™) 36 performs direct management of the processing tools 40, 44, and 48. The EQS™ 36 provides a tool communication link using a semiconductor equipment communication standard (SECS) protocol. Processing tools can be directly monitored and controlled using the communication links between the tools and the EQS™ 36.
Referring now to FIG. 2, the exemplary manufacturing system is shown specifically for the case of product running on TOOL00244. In this case, a product lot is moved into an operation step in the PROMIS™ server 24. By referencing the product routing, the PROMIS™ server 24 determines that the next operation requires a manufacturing process having a recipe name “22LM11”. The PROMIS™ server 24 information is shared with the CSN™ server 28 via the RM™ server 32. The CSN™ server 28 references the current status of the manufacturing equipment while searching for a tool capable of running the required recipe. The CSN™ server 28 makes an equipment selection. In addition, the CSN™ server 28 selects a chamber, or a set of chambers, on the tool for running this process step. In this example, the selected tool is TOOL00244. Further, the CSN™ server 28 selects a set of chambers, chambers B and C, to run the process. This selection is passed to the RM™ server 32.
The RM™ server 32 receives the tool selection, recipe name, and chamber selection information from the PROMIS™ server 24 and the CSN™ server 28. The RM™ server 32 now generates a recipe name based on these selections. The generated recipe name is a concatenation of the generic recipe “22LM11” and the specific run chambers, “BC” to form a specific recipe name “22LM11BC.” The recipe name is used to select a recipe in the tool 44 using the SECS interface of the EQS™ 36. This recipe may be verified in the RM™ server 32 by uploading the recipe contents from the process tool 44 to the RM™ server 32 and then checking the recipe contents against the RM™ server 32 run database. The EQS™ 36 then commands the tool 44 to start the process when the product wafers have been loaded.
The reason a modified recipe name must be used is illustrated by the process tool 44. The tool 44 contains a recipe manager 52. The recipe manager 52 allows a process engineer to create and to edit recipes for the tool 44. Each recipe contains the steps, the parametric settings, and the run times for a particular process variation. Typically, the recipe manager 52 is accessed through an operator interface that is built into, or attached to, the tool 44. The recipe manager 52 stores all of the recipes for the tool 44. To process wafers in a particular chamber of the tool 44, the recipe must contain the chamber name in specific reference locations in the recipe sequence. Alternatively, if multiple chambers are to be used to process wafers simultaneously, then each chamber must be specified in the recipe sequence.
In this control scenario, therefore, the “22LM11” recipe must be stored in the recipe manager 52 of the tool 44 as a large set of recipes as shown. For example, a recipe named “22LM11A” is used when product is run using the “22LM11” sequence in chamber A, but this recipe is not used for chambers B, C, or D. Alternatively, recipe “22LM11ACD” is used to run recipe sequence “22LM11” in chambers A, C, and D, but not B. Each of the “22LM11-xxxx” variations differs from the other only in regards to the chamber references in the recipe sequence.
The above-described architecture and method results in several disadvantages. First, the large number of combinations of chambers in a multiple chamber machine 44 results in a proliferation of recipes in the recipe manager 52 of that machine 44. In the example case, 15 recipes are required to cover the chamber variations for a single recipe “22LM11”. Each major recipe on the tool 44 may generate this magnitude of proliferation. This proliferation of recipes results in poor usage of the available recipe manager storage media. Further, any processing change in the recipe must be made in every one of the fifteen recipes on an individual basis. Therefore, a simple change in the recipe requires a large amount of work by the process engineer. It is very easy for the process engineer to incorrectly change or to neglect to change a single recipe variation. This can result in a significant incorrect processing event if the mistake is not caught. An improved method for handling recipe selection on multiple chamber, process tools is needed.
Several prior art inventions relate to manufacturing management systems. U.S. Pat. No. 6,334,215 B1 to Barker et al shows an application migration method involving a manufacturing execution system (MES). U.S. Pat. No. 6,256,550 B1 to Wu et al discloses a manufacturing control and reporting system capable of tracking overall equipment effectiveness. U.S. Pat. No. 5,867,389 to Hamada et al teaches an apparatus to manage recipes in a wafer production line. The apparatus provides the ability to upload/download recipes, to edit recipes, and to copy recipes.